1. Field of Invention
The present invention relates to modular refractory ceramic fiber blanket insulation systems.
2. Description of Prior Art
U.S. Pat. Nos. 3,952,470 and 4,001,996 each relate to modular refractory ceramic fiber blocks formed from folded ceramic fiber blankets for insulating furnaces and the like. In these modules, supporting rods were mounted within and extended along certain of the folds in the blankets. In the foregoing U.S. Patents, the modules were attached to the furnace wall by a channel member which extended transversely across the rear face of the insulation block in a direction transverse to the direction of the folds of the blanket of the block. Other U.S. Patents relating to insulation modules of which applicant is inventor are U.S. Pat. Nos. 4,055,926; 4,086,737; 4,103,469; and 4,122,386. These modules used channel attachment structure, as well. U.S. patent applications Ser. Nos. 245,946 and 309,594 of which applicant is an inventor are modules of similar blanket construction in which support rods penetrate the blanket near the folds adjacent the furnace wall rather than being mounted in alignment with the folds.
Another type of modules, such as in U.S. Pat. Nos. 3,819,468 and 3,832,815 has utilized wires or pins extending transversely through a number of aligned strips of "edge grain" ceramic fiber material or blanket to hold the strips together in the module. In U.S. Pat. No. 3,819,468, uncompressed strips of the blanket were mechanically attached to a board of material such as vermiculite which was then mechanically attached to the furnace shell. In U.S. Pat. No. 3,832,815 compressed strips of blanket were restrained on an inner surface or cold face by internal rods which attach to an expanded metal angle member at the sides were attached to the furnace wall.
Another type of furnace insulation, although not generally considered to be modules, impaled the insulative blanket onto spears or hangers generally parallel to the furnace walls. These spears were separate hardware items which has to be installed on the furnace wall in the field while the blanket was being attached, causing a more complicated installation, and also causing this type of insulation to not be regarded as modules. Examples of this type of insulation are in U.S. Pat. Nos. 3,854,262 and 3,892,396, and the insulation sold a "Nip & Tuck" insulation by C-E Refractories, Combustion Engineering, Inc. of Valley Forge, Pa. Also, in the "Nip & Tuck" type, the attachment structure used was such that insulation could not be removed independently of each other.
The impaled or speared blanket insulation was more difficult to install than modules, since handling of the individual blankets was required. This unduly increased labor costs and installation time. Also the impaled blanket was often not as strong as modular insulation. The "edge grain" modules typically required a special bolting or attaching tool, such as a stud welding gun, for installation against a furnace wall. Further, portions of the tool had to pass through the body of the module during installation. The prior art modules in which applicant is a named inventor offer advantages, among others, over the foregoing types of being easily manually installed by relatively unskilled persons onto washers or the like welded or bolted to the furnace wall.
In some situations, however, it has become desirable to achieve an even firmer and more positive attachment of the modules to the furnace wall. Additionally, it would be desirable to obtain an indication for the installer that this attachment has been achieved.